Plug in/thermoelectric coolers

brickman you have a remote in the sleeper to shut it off. now the only thing that would be on is the fridge. would the fridge 12v or 110 drain the batteries down over night?

you had a 1000w and wished it was bigger. what kinda stuff were you useing?

 

i was in the stores and wondering what a guy would need. if you find your in a spot where you cant idle could you use a electric heater, i can see myself getting up in a cold sleeper ( shivering lol ) then go out to check the oil before i start the truck, you could freeze your ### off before the truck got warm

 

I ordered my Igloo 12 volt from Global Trucker, who is one of our forum sponsor / advertisers. Tested mine out and it works great. Gets pretty darn cold. For the amount of cold items I'll have on the road, it will be enough. Some soda's, water, maybe some lunch meat and a small jar of mayo, mustard and jelly. Most everything else will be non- refrigerated stuff. Maybe if I get a lunch box cooker and learn to use it, I might need space for some pork chops or ground beef, but that's about it.

 

What did the igloo cost ya? shipping?

 

thats just what i,d put in it. i can live on sandwichs for the most part. it would be easy to go in the truck stop and order but i cant see wasting my money that way. plus 20 miles down the road i,d probably get the hershey squirts.

 

Are all 12V outlets created equal or are some more equal than others? Joking aside, what's the max wattage of a 12V outlet? If you plug a 450W inverter into a 12V outlet what will happen? Will you still only be able to suck 180W or can you go up to 450?

 

All 12v outlets are not the same nor are the plugs.

There are heavier duty ones available than the typical accessory type found in some trucks & SUV's.

A typical electric cooler draws about 5-6 amps continuously.
This is enough to melt the average cigarette lighter plug over a short period of time (a few hrs).

By the way, that same 5-6 amp draw over 24 rs is enough to kill the batterys...especially if it's cold out.

A heavier duty cig lighter plug will have a larger, bulkier looking tip to mate with the inside of the socket.

The larger tip dissipates a fair amount of the heat caused by the poor connection between the plug and the socket.

Still, the more current you attempt to pull through a crappy connection causes that much more heat to be generated.
More heat decreases the connection which makes for more heat.
Even the heavy duty plugs & outlets don't last long in that service.

A 450 watt inverter, like any other inverter, only draws what it needs to satisfy the load placed on it.

If the load only requires 150 watts, the inverter only produces that 150 watts.
By the same token, the inverter only draws enough from the battery to satisfy that 150 watt load plus the losses within the inverter.

A fully loaded 450 watt inverter will draw aprox 550 watts from the vehicle charging system.
At 12.8 vdc this equates to aprox 42 amps.
At 13.8vdc you need to pull aprox 40 amps thru that cig lighter plug/socket.

This is way above the safe continuous rating of any cig lighter plug/socket.
Eventually, one or the other will melt or burn.

Figuring the dc current draw for any 12.6 or 13.8 vdc device is easy.

If you know the wattage necessary to run a 110vac device, divide that wattage by the dc voltage you have available at the battery to inverter connection point.
Add about 20% more current to that because the inverter is not perfect in its conversion from dc to ac.
There's losses to be accounted for inside the inverter.

Example:
450 watts drawn by the ac load.
13.8 vdc available to the inverter (truck running).
450/13.8=32.6 amps drawn from the 13.8vdc source.
32.6 + 20% = aprox 40 amps total drawn from the 13.8vdc source.

You would use the same formula to figure the current draw of a 12vdc device.

If the 12vdc device draws 100watts:
100/13.8=7.25 amps from the battery.

Now you know as little as I do.

 

The first one I had lasted for 7 years before the motor gave out , the second one lasted 6 years. I've had my present one for 4 years. I run it off a 2000 watt Vanner inverter (made in Ohio) I've had since 1990. Home Depot and Loews have them on sale in the fall when college kids are going back to school for under $100.

 

Thanks BobC. You were very helpful.